Transient Simulation of Oxygen Stable Isotopes over the Asian Monsoon Region with the Iloveclim Model

Abstract:

The Asian summer monsoon affects the economical prosperity of vast, heavily populated regions (almost two-third of humanity). Asian summer monsoon dynamics at the orbital scale is a subject of considerable debate. Central in this debate is the interpretation of the Asian speleothem δ¹⁸O record as a valid proxy for summer monsoon intensity.

In this study, we present a transient simulation of the last 150,000 years, performed with a numerical isotope-enabled fully coupled atmosphere-ocean-vegetation model (iLOVECLIM). This enables us to assess the nature of the δ¹⁸O signal in South Asian speleothems. We discuss the validity of Asian speleothem δ¹⁸O records as a proxy for summer monsoon intensity and the ultimate forcings of Asian monsoon precipitations at orbital scale.